Efficacy of Acellular Dermal Matrix in Soft Tissue Augmentation Around Dental Implants: A Systematic Review and Meta-Analysis.

This study was done to perform a systematic review and meta-analysis of the studies on the efficacy of acellular dermal matrix (ADM) in increasing the soft tissue thickness (STT) and keratinized mucosal width (KMW) around dental implants. The PubMed, Scopus, Cochrane, Web of Science, and ProQuest databases were searched by July 2020 to retrieve relevant studies. Depending upon the heterogeneity of included studies, the weighted mean difference (WMD) with 95% CI was calculated using either fixed or random-effects model. Based on the meta-analysis of 6 studies, the effect of ADM on STT and KMW was significant (WMD: 1.07 [95% CI: 0.34-1.79], P = .004, and WMD: 1.99 [95% CI: 0.88-3.09], P < .001, respectively). Further, a comparison between the efficacy of the ADM and the control group, which included the autogenous soft tissue augmentation techniques, showed no statistically significant differences between groups (STT: WMD: 0.24 [95% CI: -0.26 to 0.74], P = .161 and KMW: WMD: -0.23 [95% CI: -0.68 to 0.22], P = .324). The subgroup analysis showed that simultaneous augmentation and implant placement were increased by 0.23 mm in the KMW, and the placement of ADM around loaded implants caused 0.5 mm decrease in the KMW, which was not statistically significant. Accordingly, it is possible to substitute ADM for soft tissue augmentation around dental implants.

A comparison of four decontamination procedures in Reusing healing abutments: An in vitro study.

Objectives: This study aimed to compare the effect of four decontamination methods on the level of residual contaminants in the re-usage of dental healing abutments. Materials and methods: In this experimental study, 50 used healing abutments were divided into five groups of ten as follows: 1. Control group: healing abutments were submerged in the ultrasonic device then autoclaved at 121 °C for 15 min; 2. Hypochlorite group: Same procedure as the control group, but the healing abutments were additionally immersed in 3 % hypochlorite for 20 min; 3. Chlorhexidine group: Same procedure as the control group, but the healing abutments were additionally treated with 12 % chlorhexidine; 4. Air polishing group: Same procedure as the control group, but the healing abutments were subjected to air polishing; 5. Hydrogen peroxide group: Same procedure as the control group, but the healing abutments were additionally exposed to 3 % hydrogen peroxide. Then, all healing abutments were stained with a protein-specific stain, Phloxine B. Five photographs were taken of each healing abutment, with four capturing the body (shank)and one capturing the top. All images were analysed, to measure the stained (contaminated) areas of each sample. The obtained data were analysed using statistical software (significance set at p < 0.05). Results: The one-way ANOVA test indicated that the average percentage of contamination residues on the occlusal surface did not show a significant difference among the five groups: control: 5.5 ± 2.8, sodium hypochlorite: 4.9 ± 2.5, Chlorhexidine: 5.3 ± 2.5, air polisher: 3.1 ± 1.8 and Hydrogen peroxide: 4.8 ± 3.1. (p = 0.26). The average percentage of residual contamination on the body surfaces (shank part) was significantly lower in the air polisher (1.7 ± 1.1) and sodium hypochlorite (2.4 ± 1.1) groups compared to the other three groups (Control: 6.1 ± 2.3, Hydrogen peroxide: 4.6 ± 0.7, Chlorhexidine: 5.4 ± 2.4) (p < 0.05). Conclusion: The results of this study showed that the use of sodium hypochlorite and air polishing, alongside autoclaving and ultrasonic cleaning, effectively reduced residual contamination on the body surfaces of healing abutments.

Isolation and characterization of human periodontal ligament stem cells under the terms of use in clinical application: A pilot study.

Background: The aim of the present study is to determine the possibility of isolation and characterization of the human periodontal ligament stem cells (hPDLSCs) using limited harvested periodontal ligament (PDL) tissue of only one patient's wisdom teeth (2-4 teeth) under the more compatible terms of use in clinical application without using the fetal bovine serum (FBS). Materials and Methods: In this pilot study, hPDLSCs were isolated from the impacted third molar, and tissue was scraped from the roots of the impacted third molar of 10 volunteers to enzymatically digest using collagenase. The cells were sub-cultured. The samples of the first seven patients and half of the eighth patient's sample were cultured in alpha modified of Eagle's medium (α-MEM) (-FBS) medium and the other part of the eighth patient's sample was cultured with prior medium supplemented with +FBS 15% as a control of the cultivation protocol. While for the past two patients (9th and 10th the α-MEM medium was supplemented with L-Glutamine, anti/anti 2X, and 20% knock-out serum replacement (KSR). Two more nutritious supplements (N2 and B27) were added to the medium of the tenth sample. Flow-cytometric analysis for the mesenchymal stem cell surface markers CD105, CD45, CD90, and CD73 was performed. Subsequent polymerase chain reaction was undertaken on three samples cultured with two growth media. Results: Cultivation failed in some of the samples because of the lack of cell adhesion to the culturing dish bottom (floating cells), but it was successful for the 9th and 10th patients, which were cultured in the α-MEM serum supplemented with KSR 20%. Flow cytometry analysis was positive for CD105, CD90, and CD73 and negative for CD45. The PDL stem cells (PDLSCs) expressed CD105, CD45, and CD90 but were poor for CD73. Conclusion: According to the limited number of sample tests in this study, isolation and characterization of PDLSCs from collected PDL tissue of one patient's wisdom teeth (2-4) may be possible by the proper setup in synthetic FBS-free serum.

Comparative evaluation of microRNA-155 expression level and its correlation with tumor necrotizing factor α and interleukin 6 in patients with chronic periodontitis.

Background: MicroRNAs are a class of small noncoding ribonucleic acids that perform a critical role in adjustment of gene expression. miRNAs-155 (miR-155) participates in controlling inflammation. Periodontitis is defined as inflammatory disorder of tissues surrounding the teeth. In this study, the expression levels of miR-155 and its target genes, tumor necrotizing factor alpha (TNF-α), and interleukin-6 (IL-6) were evaluated in a group of Iranian patients. Materials and Methods: This sectional study was performed on 10 healthy controls and 10 individuals with chronic periodontitis by means of polymerase chain reaction (PCR) test. For each individual, clinical parameters including probing depth and clinical attachment loss and blood samples were measured. Levels of miR-155, TNF-α, and IL-6 were quantified using real-time PCR (α=0/05) and the results were analyzed by Mann-Whitney U test. Results: The level of miR-155 was significantly higher in patients with chronic periodontitis (P < 0.001). A positive correlation was observed between the level of miR-155 and clinical parameters (P < 0.05). Level of miR-155 in tissue samples was correlated with blood samples although the expression level was higher in blood samples. Conclusion: As the expression level of miR-155, TNF-α, and IL-6 genes was higher in subjects with chronic periodontitis than healthy individuals, it might suggest a role for miR-155 in patients with chronic periodontitis.

Effect of leukocyte and platelet-rich fibrin on free gingival graft healing: A clinical and histological study in rabbits.

Background. Recently, the use of leukocyte- and platelet-rich fibrin (L-PRF) has been recommended due to the presence of various growth factors to increase the success of free gingival grafts (FGG). This study evaluated the effect of using L-PRF in the healing of FGG in rabbits. Methods. Twenty rabbits were randomly divided into two groups. In each group, FGG was performed in two separate sites with or without L-PRF. One of these groups was sacrificed on the 7th day and the other on the 28th day and analyzed in terms of clinical indices, including wound healing, gingi-val thickness (GT), and keratinized tissue width (KTW). Then histologic sections were obtained and stained for type and degree of inflammation and rate of vascular formation analysis. SPSS 22 was used for statistical analysis. Results. The extent of changes in GT, KTW, wound healing index, and vascular formation between the test and control groups was not statistically significant. The difference in the type of inflammation was significant only between the -7day and -28day control groups (P=0.003). The degree of inflammation between the -7day test group and the -28day control group, as well as the -7day and -28day control groups, were statistically significant (P=0.011 and P=0.002, respectively). Conclusion. Using L-PRF with FGG could improve FGG healing compared to using FGG alone, but the results were not statistically significant.

Effect of systemic administration of omeprazole on osseointegration around titanium dental implants: A histomorphometric study in dogs.

BACKGROUND: Dental implants are widely accepted substitutes for replacing missing teeth. Many factors, including the use of specific drugs such as proton-pump inhibitors (PPIs) (omeprazole), can affect the success of dental implantations. The aim of this study was to investigate the relationship between the use of omeprazole and osseointegration of dental implants. MATERIALS AND METHODS: This experimental animal study was performed on eight native male dogs weighted 11-13 kg and aged 16-20 months. The dogs were divided into two groups (receivers and nonreceivers of omeprazole). After extraction of mandibular teeth, treatment was started randomly with the administration of omeprazole and saline. After a 2-month recovery period, six titanium implants were placed in the jaws of all dogs and the administration of omeprazole was continued for 2 weeks. After 4 and 12 weeks, the dogs were anesthetized and dental implants with their bone marrow were removed. The samples were examined histomorphometrically to determine osseointegration. Data were analyzed with two-way ANOVA test for 95% confidence interval. The P value was set at 0.05. RESULTS: In the microscopic examination of the samples in week 4, the levels of bone-implant contact (BIC) in the study group were significantly lower than the control group (46.37 vs. 64.37%). In 12 weeks, BIC was significantly lower than that of the control group (67.33 vs. 82.00%). The type of bone formed in week 4 in both the groups was more woven, and in the 12th week, it was mostly lamellar. CONCLUSION: Systemic administration of PPIs may interfere with osseointegration of dental implants.

Evaluation of salivary calcium, phosphorus and alkaline phosphatase concentrations before and after the first phase of periodontal treatment in patients with chronic periodontitis.

Background: Evaluation of salivary biomarkers is a non-invasive, convenient, and economical method for diagnosing many diseases. Evidence shows that salivary biomarkers and periodontal disease might be correlated. This study was conducted to evaluate phase I periodontal therapy's effect on salivary concentrations of calcium, phosphorous, and alkaline phosphatase (ALP). Methods: In this descriptive, analytical study, 16 patients were selected from those referred to the Department of Oral Medicine, Faculty of Dentistry, Isfahan University of Medical Sciences, using convenience sampling. Salivary samples were collected using the drooling method. The salivary concentrations of calcium, phosphorous, and ALP were measured immediately after saliva collection, before the first phase of periodontal therapy and one month later, using a colorimetric assay. The data were analyzed with SPSS using paired t-test. P<0.05 was considered statistically significant. Results: The salivary concentrations of calcium, phosphorous, and ALP were 6.68, 20.57, and 48.31 mg/dL, respectively, before and 7.15, 22.51, and 40.37 mg/dL, respectively, after phase I periodontal therapy. There were no significant differences between the salivary levels of calcium, phosphorous, and ALP before and after phase I periodontal therapy (P>0.05). Conclusion: This study revealed that the salivary concentrations of calcium, phosphorous, and ALP remained relatively unchanged after phase I periodontal therapy.

Comparative evaluation of the cortisol level of unstimulated saliva in patients with and without chronic periodontitis.

BACKGROUND: Chronic periodontitis (CP) is one of the most prevalent diseases of the oral cavity with various biological and behavioral risk factors. We aimed to evaluate the association between the salivary cortisol level (SCL) of unstimulated saliva and CP in patients referred to Isfahan Dental Faculty. MATERIALS AND METHODS: In this analytic cross-sectional study, 90 patients were selected based on the presence of periodontitis and were divided into two groups: with periodontitis and without periodontitis (n = 45). First, by evaluating the level of anxiety with Spielberger State-Trait Anxiety Inventory questionnaire, each group was divided into three subgroups, each containing 15 persons. To measure the SCL in all subgroups by the enzyme-linked immunosorbent assay method, saliva samples were collected with unstimulated spitting method between 9 and 11 AM. Periodontal evaluation was done using the mean probing depth (PD), plaque index, and bleeding on probing. The obtained data were analyzed using SPSS software (version 20, IBM Corp., Armonk, N.Y., USA) and analysis of variance, independent t-test, Chi-square, Mann-Whitney, Spearman correlation, and Pearson correlation coefficient tests (α = 0.05). RESULTS: The mean level of salivary cortisol (P = 0.048) and PD (P = 0.009) in patients with periodontitis was significantly higher than those without periodontitis. There was a direct and meaningful correlation between PD and SCL (P < 0.001, r = 0.363). In both groups of participants with (P < 0.001) and without periodontitis (P < 0.001), the mean SCL in patients with high anxiety was significantly more than patients with medium and low anxiety. CONCLUSION: Our results showed that there is an increased level of salivary cortisol (as anxiety index) in patients with CP. Therefore, it seems that the probability of the occurrence of periodontitis is higher in those with increased cortisol level.

Relationship Between Periodontal Disease and Serum Factors in Patients Undergoing Hemodialysis.

BACKGROUND: Chronic renal disease is a common condition with several recognized risk factors. Periodontal disease is a recently suggested risk factor for renal disease. We aimed to assess the relationship between periodontal disease and several serum factors in patients undergoing hemodialysis. METHODS: This descriptive cross-sectional study was conducted on 57 patients undergoing hemodialysis. Periodontal examination was done by measuring the mean Pocket Depth (PD), Silness-Löe Plaque Index (PI), Ainamo and Bay Bleeding On Probing (BOP), Löe and Silness Gingival Index (GI) and Clinical Attachment Loss (CAL). Serum levels of albumin, calcium, phosphorus, hemoglobin, ferritin and creatinine were measured via a routine blood test. Cystatin C was separately measured. Data were analyzed using independent t-test, Pearson's correlation coefficient, chi square test and Mann Whitney test (alpha=0.05). RESULTS: 37 men and 20 women were evaluated. Of these, 26.3% had periodontitis and 73.7% had gingivitis. Serum level of albumin (P=0.02) and ferritin (P=0.043) in patients with periodontitis was significantly higher than that in patients with gingivitis. The serum level of creatinine (P=0.02), cystatin C (P=0.013), calcium (P=0.046) and phosphorus (P=0.037) had a significant correlation with severity of periodontitis and increase in CAL. CONCLUSION: Increase in the serum levels of albumin and ferritin was related to the progression of gingivitis to periodontitis. Also, the serum levels of creatinine, cystatin C, calcium and phosphorus increased with an increase in CAL.

The effect of buccal corticotomy on accelerating orthodontic tooth movement of maxillary canine.

BACKGROUND: Selective alveolar corticotomy is defined as an intentional injury to cortical bone. This technique is an effective means of accelerating orthodontic tooth movement. The aim of this study is to evaluate the effect of buccal corticotomy in accelerating maxillary canine retraction. MATERIALS AND METHODS: The sample in this clinical trial study consisted of 15 adult female patients with therapeutic need for extraction of maxillary first premolars and maximum canine retraction. By use of split-mouth design, at the time of premolars extraction, buccal corticotomy was performed around the maxillary first premolar, randomly on one side of maxilla, and the other side was reserved as the control side. Canine retraction was performed by use of friction - less mechanic with simple vertical loop. Every 2 weeks, distance between canines and second premolars was measured until complete space closure. The velocity of space closure was calculated to evaluate the effect of this technique in accelerating orthodontic tooth movement. The obtained data were statistically analyzed using independent t-test, and the significance was set at 0.05. RESULTS: The rate of canine retraction was significantly higher on the corticotomy side than the control side by an average of 1.8 mm/month versus 1.1 mm/month in the corticotomy side and control side, respectively (P < 0.001). CONCLUSION: Based on result of this study, corticotomy can accelerates the rate of orthodontic tooth movement about two times faster than conventional orthodontics and it is significant in early stages after surgical porsedure. Therefore Buccal corticotomy is a useful adjunct technique for accelerating orthodontic tooth movement.

Evaluation of the effect of low level laser therapy toothbrush in treatment of dentin hypersensitivity.

INTRODUCTION: Dentin hypersensitivity is one of the most common complications that affect patients after periodontal therapy. Recently low level laser therapy has been introduced as a new treatment modality and has produced beneficial results. The purpose of this study is to evaluate the effect of low level laser therapy toothbrushes in reduction of dentin hypersensitivity. METHODS: In this pilot interventional controlled clinical trial, 40 patients suffering from dentin hypersensitivity were selected using simple randomization. Half of the patients were given laser toothbrushes and the other half was given non-laser sensodyne toothbrushes. Primary dentin hypersensitivity was recorded by visual analogue scale (VAS) score and ice spray. Then dentin hypersensitivity was measured right after the treatment as well az in the intervals of 1 month and 2 months after initiation of the study. Data were compared using Statistical Package for the Social Sciences (SPSS) software and Analysis of variance (ANOVA) paired T test. RESULTS: The results of this study showed that there was a significant difference in each of the two kinds of tooth brushes separately for all time intervals (P < 0.001). Also the effect of the type of toothbrush was investigated using before treatment VAS with covariance analyses. P values for immediately, 1 month and 2 months after treatment were calculated to be 0.078, 0.02, 0.01 respectfully. Also the effect of the toothbrush type was significant in the manner that laser toothbrushes reduce dentin hypersensitivity more than ordinary toothbrushes (P< 0.05). CONCLUSION: Both sensodyne and laser tooth brushes improve dentin hypersensitivity, although the laser toothbrush led to better results in short.

Assessment of available and stable fluoride in four widely-used toothpastes in the Iranian market.

OBJECTIVE: Presence of available and stable fluoride in a dentifrice formulation is a major requirement for an anti-caries effect. Although the available fluoride concentration in Iranian dentifrices has been reported in previous studies, there is little information on its stability; which is dependent upon dentifrice formulation. This study was done to assess the fluoride ion concentration and stability in four widely used dentifrices in Iran. MATERIALS AND METHODS: In this analytical study, three samples of each brand of dentifrice (Nasim, Pooneh, Crest, and Signal) were purchased. Total fluoride (TF) and total soluble fluoride (TSF) concentrations were determined by ion specific electrodes. Data about TF were analyzed by one-way analysis of variance (ANOVA). Kruskal-Wallis and Mann-Whitney tests were used for nonparametric data (TSF). RESULTS: All dentifrices had more than 1000 ppm of fluoride ions. TSF in Crest was significantly higher than in other dentifrices (P<0.0001) and was over the maximum permitted dose. CONCLUSION: The TF concentration in Iranian toothpastes was sufficient to prevent caries.

Socket preservation using demineralized freezed dried bone allograft with and without plasma rich in growth factor: A canine study.

BACKGROUND: The accelerating effect of plasma rich in growth factors (PRGFs) in the healing of extraction sockets has been demonstrated by some studies. The aim of the present study was to histologically and histomorphometrically evaluate whether bone formation would increase by the combined use of PRGF and demineralized freeze-dried bone allograft (DFDBA). MATERIALS AND METHODS: In four female dogs, the distal root of the second, third and fourth lower premolars were extracted bilaterally and the mesial roots were preserved. The extraction sockets were randomly divided into DFDBA + PRGF, DFDBA + saline or control groups. Two dogs were sacrificed after 2 weeks and two dogs were sacrificed after 6 weeks. The extraction sockets were evaluated from both histological and histomorphometrical aspects. The data were analyzed by Mann-Whitney followed by Kruskal-Wallis tests using the Statistical Package for the Social Sciences version 20 (SPSS Inc., Chicago, IL, USA). Significant levels were set at 0.05. RESULTS: The least decrease in socket height was observed in the DFDBA + PRGF group (0.73 ± 0.42 mm). The least decrease in the coronal portion was observed in the DFDBA + PRGF group (1.38 ± 1.35 mm²). The least decrease in the middle surface was observed in the DFDBA group (0.61 ± 0.80 mm²). The least decrease in the apical portion was observed in the DFDBA group (0.34 ± 0.39 mm²). CONCLUSION: The present study showed better socket preservation subsequent to the application of DFDBA and PRGF combination in comparison with the two other groups. However, the difference was not statistically significant.

Effect of enamel matrix derivative on bone formation around intraosseous titanium implant: An experimental study in canine model.

BACKGROUND: The purpose of this study was to perform a histological, histomorphometrical, and immunohistochemical evaluation of the effect of Enamel matrix derivative (EMD) on bone formation around titanium dental implant. MATERIALS AND METHODS: In this animal study, 12 implants (10 × 3.8 mm) were inserted in the tibia bone of three dogs of Iranian breed. Two implants were placed in each tibia with EMD only on the left side. The dogs were sacrificed 2, 4, and 6 weeks after implantation. Following decalcification of the implants' surrounding tissue and preparation of 4 µm thick sections, they were stained with hematoxylin and eosin (H and E) and immunohistochemical (IHC) stain for osteopontin (OPN) marker. Histomorphometric evaluation was performed via measurement of the percentage of the woven, lamellar, and total generated bone. Light microscopy osteoblastic intensity of OPN in osteoblasts and bone matrix was also evaluated Data were analyzed by Wilcoxon signed Ranks, and Mc Nemar tests. RESULTS: In both control and EMD-applied groups, bone formation was recognized around the implants at the 4(th) week postimplantation. The percentage of total generated bone in the test group was higher than the control group, although being not statistically significant (P value = 0.917). Osteoclasts exhibited significantly higher proliferation activity compared the control group when stimulated by EMD (P value = 0.027). On average, the staining intensity in osteoblasts and extracellular matrix of bone, in EMD-applied subjects was higher than those of the controls (P value = 0.167 and P value = 0.414, respectively). CONCLUSION: EMD enhanced bone formation around dental implants, but this increase was not significant.

Comparison of fibronectin in human marginal gingiva and interdental papilla using immunohistochemistry.

BACKGROUND: The differences between marginal gingiva and interdental papilla may be due to variation in the molecular composition of these two different anatomical structures. The aim of this study was to evaluate the staining intensity of fibronectin in human marginal gingiva and interdental papilla. MATERIALS AND METHODS: In a prospective analytical study, 16 healthy subjects needing crown lengthening surgery were selected. All participants were medically healthy, non-smokers, with no medication intake, and a healthy periodontium. During surgery, facial/buccal marginal gingiva and interdental papilla were separately harvested. The specimens were subjected to hematoxylin and eosin, histochemical (Masson' strichorom, reticulin, and elastic), and immunohistochemical staining for evaluation of morphology and inflammation; assessment of connective tissue fibers (collagen, reticulin, and elastic); and determination of fibronectin staining intensity. The data were analyzed by Spsssoftware, Wilcoxon, and Spearman tests. P<0.05 was considered to be statistically significant. RESULTS: From a total of 32 specimens, 21 specimens were found to be normal or having mild inflammation, while the remaining specimens had moderate to severe inflammation in some parts. Collagen fibers were found to be dense in reticular connective tissue and degenerated in the region of inflammation. Reticulin fibers strongly stained near epithelium. Elastic fibers were sparsely found. Mean fibronectin staining intensity between marginal gingiva and interdental papilla was not statically significant (P=0.44). There is no statistically significant correlation between tissue inflammation and fibronectin staining intensity (P=0.76 for marginal gingival and P=0.20 for interdental papilla). Considering all specimens, fibronectin staining intensity of connective tissue adjacent to Sulcular/Junctional epithelium was higher than reticular connective tissue (P=0.003) and higher than connective tissue adjacent to oral epithelium (P<0.001). CONCLUSION: This study did not show any difference in interdental papilla and marginal gingival with respect to fibronectin composition. More studies in this context are needed.